The plastic sealing machine uses the principle of heating to seal photos and other materials in the middle of a transparent double-layer PVC plastic, which is waterproof and dustproof. However, the disadvantage is that it cannot exceed the size of A4 paper. It is not that the machine cannot make such a large size. Because the size is too large, it often goes unevenly during pressing and causes wrinkles, so it is generally used for pressing work cards and photos. The cold laminating machine does not heat, but evenly presses a layer of transparent self-adhesive film onto large-format photos or advertising paintings. Since it only passes a single layer, the back of the photo is not waterproof, and only the front is dust-proof. , generally used on laminate large-format photos.